CowsWithGuns

Saga complete, coming back with a summary before bed Installed the smallest kelford cams, replaced the turbo, added an NZ wiring trigger kit for good measure. No more problems, only good times. Interesting bonus feedback from the tuner is the knock threshold has improved, and there is room for more power with more boost, but he advises against it due to the stock rods + reused bolts in my motor. Back to back boost curves show no change, implying that the turbo failure had no relation to the root issue. They had no trigger issues in the first place so no reason to suspect the NZ wiring kit to be the solution. Hence, we conclude my stock cams were faulty somehow as indicated by measurements of duration (exhaust side), and the symptoms presented. Cam centrelines at 125 and 114 per kelford's recommendations, no changes made on the dyno. Car is fun as all hell, I'm traction limited in 1st and 2nd which is where most of my fun time is anyway. Major gains from 2000 rpm onwards, subjectively no change at 1500, significantly slower sub 1500. Probably due to the cams (?), but the improvement is violent at exactly 1500 so I think that's the currect VCT-on threshold and could be lowered. Regardless - car drive, car good, car fun Time to take a break and enjoy, then get some ABS and aircon back in the beast! Many thanks to everyone who shared their advice and moral support during the trouble period

Could ya'll comment on this borescope image of cyl 1? Some of the others have shiny spots or larger brown areas, or shine 'cleaned' edges, but this one has these small marks on both edges where the valves are, that may or may not be small dents (hard to tell on my resolution). What causes this, is this likely to be shrapnel?

@Kinkstaah speaking off the ill fated 7064, feast your eyes on this. What happened? Who knows. No sign of shrapnel in the manifold or the cat. Going to borescope the motor but I expect to see no damage. Perhaps the heinous noise I heard was the bearings flogged out due to getting sent to full boost on that unbalanced turbine dozens of times - if I want to engage my cynical side, this was already the condition of my 'never used' second hand turbo This is my lazy boost explanation, heck maybe the exhaust gases were going into all sorts of chaos and losing me power too (but idk). I've finished my sulk period and got my monthly pay, action time! Ordering Kelford 244As and shims, adjustable gears, replacement supercore, upgrade my triggering with something cheap and sensible. Get tuned under orders: 'give me the beans, boss' and whatever I get will be the finished build for this RB25 (except for maybe flex fuel so I can utilise the turbo fully).

Did you change the E-Throttle table? Yes, no more hole. Is the wastegate setup with correct preload? Ensure its sealing Generous preload applied, 14 psi spring, added closed loop for full duty cycle on spool up (subjective modest improvement in spool). It's those new fancy twin port IWG actuators. The top port (pushing gate open) seals per air compressor test. Bottom port does not seal, air leaks out past the piston at a decent rate. My understanding is this is by design for safety - but since you mention it - I didn't confirm that it should behave that way. Is the boost solenoid plumbed correctly? Tuner plumbed it to his preferred way after I agreed to the recommendation to ditch my 4 port. It is done like so, except the tee is using the top port of the wastegate actuator (it has the option of two fittings on top of the membrane). Is the turbo a 7064 .92 rear? I have bought something and didn't check and was wrong housing but that early dyno chart shows is what I would think is lazy for this size turbo. Yes, placard on it states so Can you do some logging in 4th gear under load and also a trigger scope? Unfortunately car is kaput until my turbo is repaired/replaced. Turboman called me today and said, 'you should come and have a look at this' with no further info so I expect to see a pile of shapnel for bearings on my lunch break tomorrow. I don't know what a trigger scope is, but I'll find out and do so once I'm back on the road. Here is some low speed 4th gear WOT spool data from what I have saved - this is at 0% duty as WG DC doesn't start until 2500 on this tune. Do you know anyone you can borrow an aftermarket CAS like a NZefi or similar? No, but I'm happy to buy one as it seems like an essential reliability upgrade anyway. I'm thinking of doing that and perhaps adding a cheap crank trigger while I'm at it soon. Since my turbo did fail within a week and I have confirmed oil supply, did pre-oil with a syringe til it dripped out, it's plausible it was f**ked from the beginning and that may explain the lazy spool.

Forgive me Father for I have sinned by proliferating misinformation online. From the r34 service manual translated to English: My cam nose heights are roughly in spec, and it appears the stock DET NEO lift would be at most 7.63mm (assuming a 32.00 round, I measured slightly above that). There is the open question why Tomei says the factory lift is 8.7mm. Begging someone who has some old DET Neo cams rotting in storage to whip out the ol' calipers or micrometer and present their factory high lift big boys Despite my turbo failure, my blade speeds were +/- 5% of what is expected from matchbot so during its one week lifespan I can only assume it was fine. And I made identical peak power on a much bigger turbo. My mate helped me do some more detailed data analysis and nothing seems out of place on the tune and sensor side. Any ideas guys? I'm back to square one. I NEED A HERO!

Occurred in 2021. f**kers raised the price substantially over the quote on the phone, and tried to force in extra work I explicitly didn't want. YMMV. But theres a reference for ya. Didn't get it balanced and didn't need line boring. Should have got it balanced (get it balanced).

Sounds like you have engine issues. Compression and/or leakdown test would be my first call (either gain peace of mind or rip the bandaid off) followed by fuel pressure check, vacuum leak check to get your basics covered. IDK where you're at with tools but I've had great luck with ebay fuel and comp testers, and my ebay leakdown went straight to the bin. Assuming your starting issues are related to the power issue, I wouldn't expect the exhaust to be a (major) concern as if it was really blocked you'd be flatlining power early and it would be fairly obvious. Nothings impossible though!

This is becoming something of a dark comedy. I will be spending some additional time in this relentless purgatory of R34 ownership. Two days ago I noticed a pretty loud tinking noise from my engine bay at idle. After reassembling the car after my camshaft investigation, I went to track it down. Tinking coming from the turbo... it's f**king siezed when you spin by hand (but spins perfect (visually) when engine is on). Inbound removal and offloading to a turbo shop with clear instructions: fix. Cherry on top, I started the car for just a second to confirm oil supply and discovered what turbo oil supply is like. Generous, in abundance, and over all surfaces great and small in the engine bay. @Kinkstaah few more moments like this and I'll be on my way to saying damn it all to hell, lets put an LS in it.

I was seriously considering this and it would be a wonderful explanation/conclusion, however my camshaft is marked with U6. Photos online of a DET neo exhaust cam have U6, whereas DE Neo has U7, so I don't think this is the case. I went ahead and measured a few extra lobes and they are all 6.9 - 7.3 (variance primairly due to measuring error with adjacent parts screwing my caliper alignment). They really don't look that worn, so I'm disturbed. Intake cam measures up perfectly normal, is cast with 'U8' (but it could also be U6, the marking is rough as guts), and the lobes are taller than on the exhaust (by about 1-2mm) just by looking at it. Height 39.5 Round diameter: 32.4; net lift = 7.1 Casting U6

~0.3mm on intake and ~0.5mm on exhaust. These are the measurements I took via feeler gauges prior to reshimming:

Made a degree wheel and took some measurements. I could not find details on stock camshaft duration and position at 1mm, so I am using the smallest tomei 'drop in' camshaft as a sensible reference for duration. My dial gauge was really really touchy and would move around 0.2mm give or take, due to the scuffed clearance to the lifter (sometimes rubbing on the camshaft)to take to access the valve, so give a generous tolerance to my measurements. I don't understand camshafts enough to have confident conclusions, but my observations and thoughts are: Intake cam seem dead on perfect, HOWEVER, my lift measured is 8.5mm (caliper), ~8.6mm (dial gauge) and the factory spec is 8.4 according to Tomei. Strange but does not worry me too much. Exhaust cam seems totally rooted! Cam lift spec is 8.7mm and I measure 7.2mm with calipers and 7.0 with dial gauge. Accordingly, my duration is 20 degrees lesser than my intake cam! The lobe centre is also advanced by 5 degrees (+/- say... 3 degrees), but the significance of that is lost on me pending further study. Edit: measured two other random lobes, both ~7.0 to 7.2 on calipers. The nicest, shiniest unworn looking lobe was 7.0 ?? Is it reasonable or at all normal for a camshaft wear out that much? The engine ran on very loose clearances (up to 23 thou) on the exhaust side for some time, I reshimmed in Oct down to 18/19 thou and the valve train noise settled a lot. Would this wear be a symptom of those loose clearances or the cause - or is it both in a vicious cycle? In case the clearances tell a story, here's my notes from Oct: Here's two pictures of lobe 1. To me it looks fine? My amateur eye is looking at lobe 3 and thinking that looks crap, but I would have not thought much beyond that (until now). So I assume the path forward is to get a spare factory exhaust cam or a pair of mild kelfords, and then adjustable cam gears on both sides and reshim them tight. Zip it up, back to the tuners, and miraculously find another 60+ horsepower and achieve The Goal. But what could have caused this problem to begin with?

The tuner on whether I am knock limited and the possibility of more timing advance: "Regarding the ignition tables, the values we have in there are on par with the other 25neos we have tuned and are confident in where they are set. I’m not sure what values you’re comparing as the table axis was originally set to MAP but have now been changed to display that axis as MGP. That can make it a bit confusing to compare to different tunes if they have their tables set up differently. But as far as the it being knock limited, yes that is the case in the low end/mid range as it comes onto boost but that is typical on this sort of setup and yours didnt seem any worse than usual. " I don't know what to make of all this. Ye wise SAU veterans say the advance is less than normal - my tuner says it's normal. I went on a hunt to find tuned, well performing neo files online to see for myself but only found one (admittedly with ~2 deg more advance on the top end) but that's a sample size of 1 lol. No doubt they are out there so I just need to search harder. Does anyone have a comparable R34 tune file that performs mint for me to look at? I also received this as my final result.

Here is a WOT run in 2nd gear after I fixed the throttle target table. Unfortunately I don't have anywhere nearby where I can full send in 3rd or 4th. What indicates this to you? I haven't done it yet but can do - just curious what gives that away to you? I also turned on closed loop just for stage 1 clamp. I feel like my spool improved a decent bit afterwards, but that could just be placebo. Interesting you say this. I noticed on my previous build (stock throttle) that in first gear the car definitely felt more powerful at something like 80-90% throttle rather than all the way, but only some of the time. I thought I was going crazy. PC Datalog - 2024-02-8 2;32;37 pm.llgx

Hahahahah, well spotted gang. Here's the story there: I put in e-throttle and tuned it to driveable state so I could drive to the tuners. That's my work there (noob me didn't fill right but interpolated vertically, and didn't realise theres more to the table). Tuner never noticed it, never ran into issues. On the drive home I experienced what felt like a boost cut protection at 6000 rpm and found that after slewthing the next day. I decided not to bring it up here as on the dyno TPS was still 99% so it wouldn't be relevant - and I didn't want to highlight my ineptitude on the laptop I ended up emailing the tuner just to verify there wasn't some strategy there but realised that this was definitely my work lmao.

Yeah, I've been hung up on that. Ok, latest and greatest action plan is 1. Verify my cam timing, attend to it as required. If I need to take timing belt off for any reason, adjustable gears (and the boost doc VCT adjustment thingo) are going on - only wish I knew their value in the past. And yes, stock cams. I forsee nothing to gain by upgrading to some mild kelfords or poncams, but happy to be told otherwise. 2. Get it on a dyno again with explicit request to optimise ignition advance (not that this is something that should need to be said but anyway...). Things are looking a little grim for the recent tune, but honestly just the constant comms and the tuner chatting to me for a full hour after I arrived really did put them in my good books so I'll *probably* take it back - and he had a folder full of powerful R34 dyno logs I glanced at so I'm erring on 'theres a reason for this' rather than incompetence or otherwise. Regardless, I will contact and ask - and the answer will guide my decision on return, or f**k it and gamble with tuner #4. I'm time and money poor but thankfully only acutely. I did just spend 3 fulltime weeks and like 10 grand on this build over xmas + tune/diag fees. Will probably not have more to share until I do the above... and I could do with a rest - this whole procedure has taken a toll. Huge thanks to everyone for your support! Maybe there will come a time I will be the one with a happy car and a brain full of experience to share here

I saw this curve in person on the dyno screen. My VTC on graph was making substantially more power the WHOLE way and touched at 6500. This is now relying on my eternally questionable memory but I saw that, and hence was really keen on my degree wheel plan. Tyvm for adding confirmation, and no hahahaha I'm not touching that shit. I still think there's a cam issue, just I'm time poor atm and cannot check imminently (I also need to figure out how the hell I'm going to mount my degree wheel without gutting my radiator and crank pulley if at all possible lol)

Thanks Lithium, I see what you are saying. This is the point where I get stressed because how do you diplomatically contact a tuner and express these ideas. Cars are much easier than people, especially when money and reputation is involved This one will be on me to figure out though. On the more fun technical side of things, can improving the timing table (approaching MBT) influence the VE map? If I understand correctly, timing will not influence the actual cylinder VE, but it will improve my torque. This is where I get a bit lost, because I thought the VE table will match the torque curve (if everything is working right); but timing also shifts the torque curve without changing the real VE? I'm only referring to 'modelled' tuning as that's all I've played with. IDK what 'traditional' even means. Anyway, what I'm thinking is lets say my timing is perfectly advanced to knock limit or MBT. My lambda should not change, so my VE would not change - but my VE still seems to fall off HARD, and my VCT disengagement point is very high. Are these things related or separate in your eyes?

The ECULogging has not been ideally set up so it didn't catch the new turbo speed sensor(I was hoping to harvest PC logs from the tuner but those don't exist). I snapped some pics that may be meaningful from my drive so far, but it's pretty lackluster data. Traffic and all that. When I get a chance I will try to a full range pull in 3rd so I can fill my compressor map accurately. For some context this is the map I got from the old tune on same engine and ECU, with the big turbo and old bolt ons. Don't look too dissimilar to my untrained eye so probably a good sign for both maps that it's what the car wants? Edit: I recall now I retarded the whole boost map by 1 degree for the drive to the tuners on the new build, hence most of it looks like it got hit by a -1. Now resisting a strong urge to +1 every cell that hasn't changed since the tune... which now that I look at it is... all of them? Not filled with optimism that this is optimised now, as you pointed out Lithium! And yes, I vibed from the tuner that he's not confident in the setup, there was an implication that it's not worth it until the root issues are resolved. This was the tune that I considered catastrophic and I spent an eternity f**king around to get it driveable (I'm talking clutch in stalling, zeroed accel enrichment table etc), but the WOT felt good and obviously didn't have knock or I wouldn't be here to talk about it The VE table looks nice but it didn't follow the torque curve as it also nosed off. The whole thing relied on closed loop lambda to function. Hey, at least it forced me to learn a lot, mainly that road tuning by holding brakes is miserable, and there's more margin for error than I thought The ECULog is a mystery to me. I only had a couple, seems to fill up really fast and I have no context for any of it. And limited sensor data. I believe that was the last pull (based on ECU log history) so it was probably a final check of some sort. I noticed the boost controller doesn't turn on until 3000 rpm - not loving that. When I redid my previous boost map on the old tune (mind you, heavily relying on closed loop) I had great spool gains by setting it to 90% (the stage 1 control) until a few psi below my target. The current boost map is open loop only, though it's otherwise spot on. I will dabble with turning on closed loop control and add 3 stage with some gentle PID settings, and then reassess my boost threshold and spool on the low end. But to be clear, it definitely doesn't FEEL bad and I agree it's a red herring here. Probably. Hard to gauge as my car experience is 'this car now' and 'this car before' lol

Data acquired!! VE Table VE Map Ignition Table WOT Dyno Run from ECU log Had a crank no start upon arrival due to a hilarious shorting issue, which was prompty resolved by the tuner (their fault, their instant resolution :D). Since I'm paranoid about everything now I noticed the log initially tracks the RPM fluctuations then becomes a flat line. I guess this is a normal noise filtering process but don't know, can anyone confirm it's normal? Also attached is the complete tune file, the ECU log with the last dyno run, and my PC log of my drive home just to be extra comprehensive. Feedback from tuner: Unusual rich spot at 4500 rpm during WOT. It isn't clear why, but the tuner suspects the wastegate flapper is blowing open for a moment... that doesn't entirely make sense to me, but regardless as it contradicts any sensible VE patterns he chose to leave it alone. VE curve shits the bed at high RPMs (following the torque curve) compared to other comparable R34s, implying it is not signal issues but mechanical issues like airflow. Tune review: Now that I've got the car back, happy to say I was at JDM Motorsport Brisbane and am pleased with them, despite this unresolved problem. I got the car back and the driveability and 'fine details' feel excellent in street conditions. Accel enrichment, idle, throttle etc feels spot on and the communication was 10/10... definitely more costly than the average shop though. The peak boost RPM in the data looks lazy compared to what I expected from a small twinscrolled EFR, but coming from the GT3582 it still feels like heaven on earth for street duties. Current diagnostic plan When time permits I will make a degree wheel and verify TDC and camshaft positions. I'm suspicious because my VCT 'off' crossover point was 6500 rpm on the dyno logs I saw on screen. This seems very high given theres graphs like below online (though I believe this is a non neo RB25). Pending further wisdom, I conclude that gaining power from idle to 6500 with VCT enabled means camshaft position is scuffed. Also GTSBoy and Fletch said so 😁 7-2-24 drive home from JDMM.llgx ECULog887 - contains WOT run.llgx 7-2-24- JDMM Tune.pclx

Custom shitshow by yours truly: 4" dump to 4" oval underneath, to 5" body highflow cat, to 3" catback. Backpressure measured by tuner and backpressure is 'low'. Mainline hub dyno on unknown 98, I don't recall where I filled last. Does this matter? Is BP or whomever higher octane than other brands? And spot on, the goal is best drivability in the 280-300kw range on 98. I don't think I clarified this before actually - it's currently running 14psi spring in the turbosmart 2 port IWG actuator, using the stock Pierberg boost controller, using a T to connect to both ports. Rocked up to the tuners with a 4port and 7psi spring, they immediately said get rid of that because it has insufficient resolution for my low boost. Winning - employing new tech now No comments on knock, the tuner was perturbed by the high WGDuty% to stop boost falling off, and the low power in general. I did something very similar when I was staring at the cheap 7064 for sale. This made me think I might have a nasty fall off past ~6000 rpm until the rude surprise So tuner has recommended I throw in the towel as further diag will be expensive guess work. I'll get all the logs and data I can (they are doing a final tune check/run now) and post them up here, and slowly do my own diag at home.

Awesome input Lithium, much food for thought. You caught me pants down forgetting that approaching turbo speed limit at low PR takes me to efficiencies so low they don't get mapped . I'll be getting dyno log data hopefully on Tuesday. 1) I'm pretty sure it's running the stock plenum because it's running the stock throttle body. They mentioned checking it because my 60mm bosch looked tiny (but its actually stock size internally). I'll ask directly out of interest. In all honesty, when I agonised over getting a plazmaman plenum (or not) the forums implied to me that any aftermarket plenums are all super doo-doo with extra poo, and are only worth considering (for performance reasons) if chasing peak power gains well beyond my 300kw benchmark. I concluded the plazmaman is the least poo of the steaming pile but still not desirable for a street oriented car. I guess you beg to differ? For the rest of the points, I may have to ask some stupid questions so forgive me - this is my first project car so I'm rife with uncertainty. 2) This can be verified by confirming MAP is at 18 psi the whole way? 3) Will check the logs for speed data (and double check I didn't put in the wrong scaling number ), but the system has been boost leak checked both by me and tuner: I did 30psi with a soap spray bottle, and by the tuner with smoke and low pressure (8psi). 4) When I saw that graph, I was suprised that I'm not seeing a faster spool (and hence more low rpm power) than the 3076 - which I expected with this turbo. Do you suggest/agree that the whole graph may be underperforming, rather than just 5k+ rpm? 5) No idea. If I or the tuner physically inspect the TB behaviour with engine off (or just snapping it open at idle), and then see if this aligns with the sensor data, would that be satisfactory for the rest of the rev range? I have a general question - if I have an IWG that has the flapper blowing open that isn't treated by increasing duty cycle, how do you fix that properly? Is it just a case of bigger springs and/or more preload or is there a 'trick'? While you're around about lithium, could you share what turbo setup you would recommend for my goals if the 7064 is not it? It's too late for me now but I'm still curious. FWIW I wanted the 7163 0.85 IWG... but maybe I should get over it and fork out for the EWG life like everyone else 😛

Am I onto something here? Another blokes picture of a VCT gear (btw, is this what you would call a cam phasor?) looks like this. Note the position of the red dot to the bolts and the timing mark. Mine looks like this, pardon the image quality. So the bolts are in a substantially different position, and my red dot is below the timing mark - theirs is above. Like... this is the issue right guys????

Close of business, got report from the tuner. No diagnosis - fat bill for the week. But they have tested everything advised so far before I mentioned it. CAS wheel has been changed a year ago to a 24 tooth (nissan opto in da bin) Timing light is steady under load on dyno Visual inspection of mechanical timing is good (including faulty balancer) VTC gear and electronics work correctly Boost leaks retested, BOV inspected Valve float assumed a non issue due to aftermarket heavy valve springs, boosted only to 18 psi No boost rags Cross checked by adding a MAF pre throttle body Statement that my loose valve clearances would not cause this issue (though they don't love it). I will request ECU logs but I won't get these til Tuesday. Times are tough mates. The team said they will give it a good think over the weekend and maybe there will be some eureka moment - but at this point I'm getting myself prepared to accept that I'll be running a fully sick 240kw for another year.

Yep sorry, I believe it is going out the exhaust in generous volumes, except in a very narrow crank angle range. Then it slowly exits out the oil cap and nowhere else. Is that what you would expect then?

Yeah, I was chatting with you a while back on turbo selection and you definitely made it clear to me that 300kw on the small EFRs may not be happening. I am very much at peace with that! On the other hand, it's also what motivated me to go a bit 'extra' on things like a fatty dump pipe because I thought it would be a cool post to share here if I did crack 300kw on an IWG 7163 or 7064 on 98. If an underlying issue gets rectified and I get it back at say 290, I will be VERY happy, and also motivated to minmax things (e.g. supreme intercooler ducting, heat shielding out the ass etc) for science and to flex my 'big' power small turbo Hit the winter time dyno for internet points